I like XFCE use it since RC1; A little problem in RC2 is, when
I run two applications, sometimes both stop responding with the
windows couldn't be restored and titlebar blinking. I cannot figure out more.

I downloaded the final XFCE-v1.2 and run it twice,

the 1st time: started successfully; logged out, then tried to login as root--I just cannot do this
because no login window appear at all; It went back to the original guest window
automatically; adjusted fontsize; tried several functins, but for unknown reasons, screen
became a dark board. had to power off. switch on again, XFCE didnt appear at all.

reinstalled, and tried for the 2nd time: only the mouse arrow works fine, nothing else appear on the screen.

my USB key is in ext2 format,
the other problem is : lilo bootloader show "KDE, LXDE..." but it is an XFCE environment when started.

copy that file to /boot/syslinux in your porteus installation, and then make it executable:

chmod +x liloinst.sh

then, delete /boot/lilo.conf and /boot/lilo.map, and run lin_start_here.sh to install this new configuration.

I am hopeful that this will solve your problems with logging into the system. Given the missing 'xfce' cheatcode from your lilo config, the system is probably trying to boot into lxde which, of course, it cannot find. Please let me know how this goes and if you run into any other trouble.

I've not experienced the issue you had in rc2 with applications freezing -- please let me know which applications you were using so I can test this and also please try testing this behavior in 'Always Fresh' mode, to make sure you don't have something from your saved changes or extra modules that might be causing this.

Many thanks and once again, my apologies!

Please take a look at our online documentation, here. Suggestions are welcome!